Automobile heater



Feb. 20, 1940. H. J. DE N. MCCQLLUM 2,19l,'77 AUTOMOBILE HEATER OriginalFiled Jan. 28, 1936 NEN QON @N @NN QQN jlzvezai 01'? family Je/c COllmMQQM Patented Feb. 20, 1940 UNITED STATES AUTOMOBILE HEATER Henry J. DeN. Mc

Gollum, Evanston, Ill.

Original application January 28, 1936, Serial No.

61,213. Divided and 1938, Serial No. 200,3

5 Claims.

The invention relates generally to automobile heaters and the presentapplication is a division of a co-pending application, Serial No. 61,213led January 28, 1936.

More particularly, the present invention relates to the operation andcontrol of the independent heat generator illustrated and described insaid copending application when the heater is so installed in anautomobile as to employ the vac- LO uums created by internal combustionengine for a source of power to provide the fluid pressure differentialneeded to produce and move a stream of hot gases through the radiator ofthe generator.

In view of the fact that the degree of vacuum developed in the intakemanifold of the internal combustion engine of an automobile approacheszero from time to time, depending upon the speed and the load to whichthe engine is subjected a under operating conditions, as when theautomobile is being accelerated or driven up a hill, it is appreciatedthat now and then the vacuum developed in the intake manifold will fallbelow the degree necessary to maintain the factors of com- 35 bustionrequired for a continuous operation of the heat generator. Consequently,it is necessary to provide for a reignition of the combustible mixturein the generatorkso that the operation of a heater may be resumed whenthe vacuum B0 factors are again favorable. Moreover, other contingenciesarise when the combustion has ceased for a while and these have to becoordinated with the rei'gntion to return the heater to proper and fulloperation.

B `One of the objects of the invention is to provide for the reignitionof the extinguished flament an internal combustion heater when thefactors are again favorable therefor and to coordinate therewith theother functions necessary to return l0 the heater to full operation.

Another object of the invention is to provide a liquid fuel burningheater with improved means for maintaining a flame and reestablishingthe flame, should the flame be accidentally extinguished.

Another object of the invention is to provide an improved means forreigniting and returning the heater to full operation automaticallywith- 50 out attention from the operator when the factors preventing theoperation of the heater are removed either after a short or a longdelay.

Another object of the invention is to provide a heater and controltherefor of the'class described, which is relatively simple inconstruction and 1this application April 6,

may be economically manufactured, installed,

operated and maintained.

These being among the objects of the invention, other and furtherobjects will become apparent from the drawing herein, the descriptionrelating thereto and the appended claims.

Referring now to the embodiment of the invention illustratedIdiagrammatically in the single view of the accompanying drawing, theheater construction, which is more particularly de-A scribed in saidcopending application, comprises generally, a carbureting device I 0which supplies to the heater I2, as indicated by the arrow I4, severalcombustible mixtures of diierent degrees of richness to take care of thevarious heater requirements encountered under starting and runningconditions.

The combustible mixture supplied to the heater is fed into thecombustion chamber I6 in a suitable manner and the mixture is ignited byan electrical heating element I8 located in a recess 20 in the side .ofthe chamber. A refractory ceramic plug 22 is disposed at the outlet ofthe combustion chamber to maintain an ignition heat since it acquires asu'iciently high temperature for such purpose by being directly exposedto the flame during the normal operation of the heater.

From the combustion chamber, the hot gases pass through a radiator 24comprising a circuitous tube 26 to which heat radiating fins 28 arethermally connected. Over these fins air is circulated by a motor 30 andfan 32 whereby heat is transferred from the hot gases of combustion tothe passenger compartment of the automobile for the comfort of thepassengers.

The outlet .of the circuitous tube '26 is connected to the intakemanifold of aninternal combustion engine and in this way the fluidpressure differential necessary for the operation of the heater issupplied whereby the combustible mixture is drawn from the carburetingdevice I0 into the combustion chamber I 6 where it is ignited and thehot gases of combustion thereby created are then drawn through theradiator 24 in heat transfer relationship. Finally, the gases aredisposed of in the intake manifold where any excess of fuel not alreadyburnt or utilized may be employed in the operation of the engine itself.

'Referring now to the operation and control of the embodimentillustrated in the accompanying drawing, it will be appreciated asalready mentioned that upon occasion the intake manifold vacuum may beso small that the rate of flow of combustible mixture into thecombustion chamber I6 will not be suiciently rapid to support the flame.Itwill, therefore, be necessary, upon occasion, to reignite the name.For this purpose, an automatic means is provided for reconnecting theigniter I8 to the source of current during the time that the vacuum istoo low for the continued operation of the heater. particular embodimentillustrated employs' a vacuum control switch which is automaticallyclosed upon the lowering of the intake manifold beyond a predetermined'value, and although shown in use with a high resistance heating elementsuch as the igniter I8 illustrated, the switch is also useable inconnection with a spark plug type of igniter.

In the embodiment illustrated, the switch is controlled by a ilexiblediaphragm 821 mounted in a suitable casing 84 and carrying a contactpoint 86 which is cooperable with a contact point 88 carried at the endof an adjustable screw 90. The contact 86 is connected by a flexibleconductor 92 in a binding post 94, insulated from the v casing 84. Theright hand side of the casing 84,

as viewed in the drawing, is connected by pipe 96 with a chamber 98. Thechambery 98 communicates with a tube |00 through a restricted passagewayI02and with the atmosphere through a similar restricted passageway |04.The left hand side of the casing 84 communicates with a`V chamber |06through a connecting tube |08. The chamber |06 communicates with theintake manifoldthrough a restricted passageway IIO and communicates witha combustion chamber I6 of the heater through a restricted passagewayII4. The passageway II4 is of slightly greater diameter than thepassageway |04.

The igniter element I8 has one end connected to the binding post 94 anditsother end connected to the battery II6 through a manually operatedswitch II8. The adjustable contact 88 is connected by a conductor |20 tothe battery II6, completing the igniter circuit. The fan motor 30 hasone terminal thereof connected with the conductor |20 and the otherterminal thereof connected to a thermostat switch |24. The main switchII8, when closed, is adapted to complete the circuit to the fan motor 30(providing the thermostatic switch I 24 is closed) through a conductor|26. Upon closing the switch II8, the

. circuit through the igniter I8 will be completed,

since the switch contacts 86 and 88 operated by the diaphragm 82 willnormally be closed. When, however, combustion commences in thecombustion chamber I6, the switch contacts 86 and 88 willbe separatedbecause' of the differential in pressure upon the opposite sides of thediaphragm resulting from the starting of a flame in the combustionchamber.

Prior to the ignition of the flame, the degree of vacuum present uponopposite sides lof the diaphragm 82 will diier because of the diierencein the diameters of the passageways |04 and II4. Since the passageway|04 is the smaller, the degreeV of vacuum produced in the chamber 98(and hence in the right handside of the casing 84) will be higher thanthe vacuum in the chamber |06, because the tendency to high vacuum inthe chamber |06 will be more completely relieved by virtue of thefactthat the passageway II4 is' `of relatively large diameter. As aresult, the diaphragm 82 will be flexed to the right, closing Vthecontacts 86 and 88.

The'

owing through the passageway I I4 are expanded by virtue of their hightemperature, the rate of owof gas (by weight) through the passageway II4will be less than the rate of flow through the passageway |04. As aresult, a higher vacuum will be built up and maintained in the chamber|06 than in the chamber 98. The diaphragm 82 will, under thesecircumstances, be ilexed to the left, separating the contacts 86 and 88and opening the circuit to the igniter I8. Since the igniter I8 draws arelatively large current, it is desirable that it be connected to thebattery for as short an interval as is necessary to ignite the iiame.

Should the ame in the combustion chamber become extinguished, the gasesdrawn through the passageway I I4 will be at a low temperature, and as aresult the rate of flow of gases (by weight) through the passageway I|4will exceed the rate of flow through the passageway |04, and as aresult, the vacuum within the chamber 98 will become greater than thevacuum in the chamber |06, causing the diaphragm 82 again to ilex to theright and complete the circuit to the igniter.

If desired, the right hand side of the diaphragm 82 may be opened to theatmosphere and a spring utilized to press the center portion of thediaphragm to the right and to maintainthe contacts 86 and 88 closed. Inthis instance, the spring will apply just suiicient force to maintainthe contacts closed when cold air is flowing through the passageway II4,but will not apply sufficient force to hold these contacts closed whenthe vacuum in the chamber |06 is increased upon the ignition of theiiame in the combustion chamber.

Consequently, the embodiment shown and described provides a physicalembodiment accomplishing the' express and implied objectsof theinvention and although a single embodiment has been 'shown anddescribed, it will be apparent to those skilled in the art that variousand furthen uses, modifications and changes may be made withoutdeparting from the spirit and substance oi the invention, the scope ofwhich is commensurate with the appended claims.

What is claimed is:

1. In a heater for an automotive vehicle having an internal combustionengine, the combination of a combustion chamber, means to supply amixture of liquid fuel and air to said combustion chamber, 'a radiatorfor receiving the products oi combustion from said chamber, a connectionfrom said radiator to the intake manifold of the automobile engine `todraw the charge of combustible mixture into said combustion chamber andthe products of combustion through said radiator, an electricallyoperated igniter in said combustion chamber, a source of electricity forsaid igniter, and means for connecting said igniter to said sourcewhenever the degree of vacuum in said intake manifold fails below theminimum required to cause flow of the combustible mixture into saidchamber ata sufficiently rapid rate' to support a flame therein, and todisconnect said igniter from said source when the degree of vacuumexceeds said minimum value, said last named means lcomprising a casing,a movable wall separating said casing into two compartments, a switchoperated. bysaid movable wall, a rst chamber connected to one of said Icompartments and having a port communicating with the intake manifoldand a port communieating with the atmosphere, and a second chamberconnected to the other of said compartments and having a portcommunicating with said com- 1 bustion chamber and a port communicatingwith the intake manifold.

2. In a heater for an automotive Vehicle having an internal combustionengine, the combination of a combustion chamber, means to supply amixture of fuel and air to said combustion chamber, a radiator forreceiving the products of combustion from said chamber, aconnection-from said radiator to the intake manifold of the automobileengine to draw the charge of combustible mixture into said combustionchamber and the products of combustion throughsaid radiator, anelectrically operated igniter in said combustion chamber, a source ofelectricity for said igniter, and means for connecting said igniter tosaid source whenever the degree of vacuum in said intake manifold fallsbelow the minimum required to cause flow of the combustible mixture intosaid chamber at a suiilciently rapid rate to support a flame thereinfandto disconnect said igniter from said source when the degree of vacuumexceeds said minimum value, said last named means comprising a casing, amovable wall separating said casing into two compartments, a switchoperated by said movable wall, a chamber connected to one of saidcompartments and having a port communicating with the intake manifoldand a port communicating with the atmosp-here, a second chamberconnected to the other of said compartments and having a. portcommunicating with saidcombustion chamber and a port communicating withthe intake manifold, said combustion chamber connecting port beingslightly larger than the port communicating with the atmosphere, wherebythe vacuum in said lrst chamber will be greater than the vacuum in saidsecond chamber except when gases flowing through said combustion chamberconnecting port are heated to a temperature resultant from normalcombustion in the combustion chamber, said means comprising a pressureoperated switch, and means responsive to the temperature of the gasesleaving said combustion chamber to control the operation of said switch.l

3. In a heater for an automotive vehicle hav ing a passenger compartmentand an internal combustion engine, the combination of a combustionchamber, means to supply a mixture of liquid fuel and air to saidcombustion chamber, a radiator for receiving the products of combustionfrom said chamber, a connection from said radiator to the intakemanifold of the automobile engine to draw the charge of combustiblemixture into said combustion chamber and the products of combustionthrough said radiator, an electrically operated igniter in saidcombustion chamber, a source of electricity for said igniter, and meansfor connecting said igniter to said source whenever the degree of vacuumin said intake manifold falls below the minimum required to cause ow ofthe combustible mixture into said chamber at a suiliciently rapid rateto support a. flame therein, and to disconnect said igniter from saidsource when the` degree oi vacuum exceeds said minimum value, said lastnamed means being critically responsive to the heat expansion of the hotgases of combustion in said combustion chamber as distinguished fromunburnt combustible mixtures supplied thereto.

4. In an internal combustion heater for use with an internal combustionengine having an intake manifold, a combustion chamber, means to supplya combustible mixture of liquid fuel and air to the combustion chamber,means to connect the combustion chamber to the intake manifold, anelectrically operated igniter in the combustion chamber to ignite thecombustible mixture, a source of electricity for the igniter, and meansfor connecting the igniter to said source whenever the suction in theintake manifold falls below a certain required minimum and to disconnectthe igniter from said source when said mixture becomes ignited, the lastnamed means comprising a casing, a movable wall separating the casinginto two compartments, a switch operated by the movable wall, saidswitch adapted to close a circuit between the igniter and said source, achamber connected to one of said compartments and having a portcommunicating with the intake manifold and a port communicating with theatmosphere, and a second chamber connected to the other of saidcompartments and having a port communicating with the combustion chamberand another port communicating with the intake manifold.

5. In a heater of the class described which depends for its operationupon the suction in the intake manifold of an internal combustionengine,a combustion chamber, means to connect the combustion chamber to theintake manifold. means to supply a combustible fuel and air mixture tothe combustion chamber under the influence of said suction, an igniterin the combustion chamber to ignite the combustible mixture passingtherethrough, a source of electrical current supply, a switch adapted tocomplete a circuit between the igniter and said source to energize theigniter, and automatic control means to open and close said switch, saidcontrol means comprising a chamber vented to the combustion chamber andto the intake manifold, and a pressure sensitive element movable to openand close said switch under the influence of gas pressure in saidchamber.

HENRY J. DE N. MCCOLLUM.

